218 THE JOURXAL OF BOTANY 



REVIEWS. 



A Text-Book of Mycology and Plant Pathology. By John W. 

 HARSHBEftaER, Ph.D. With 271 illustrations. Lundon : T. & 

 A. Churchill, 1918. Price 15«. net. 



A good text-book is o£ great importance to teachers as well as 

 to students. It is convenient and even necessary for the teacher to 

 have by him a ready reference to the whole field of study ; the student 

 and practical worker requires, in the maze of subjects, a gviide which 

 he can consult at any moment. Dr. Harshberger in this volume has 

 set himself to provide a text-book that will be useful to teacher and 

 student alike. It is, he tells us, the outcome of twenty-seven years' 

 experience as a teacher of botany, during which time five years were 

 devoted to a course which combined with a study of mycolog}'', 

 "a parallel study of the most important cultural and inoculation 

 methods used by the practical bacteriologist and mycologist at the 

 present day." 



In the table of contents we find a well-planned and full resume 

 of the different svibjects dealt with. 



In presenting a study covering the vast range of subjects included 

 under modern mycology, a judicious choice is necessary if overweight 

 is to be avoided : readers, we are sure, will recognize that though 

 there has been much curtailment, there is no aspect of the study that 

 does not receive a share of attention. In part i. (269 pages) the 

 author has given a general study of Mycology ; the other three parts 

 <(398 pages) are concerned with plant pathology in all its branches. 

 There are several appendixes in which are set forth a series of labora- 

 tory exercises, keys to special fungi groups, advice to collectors, &c. 



Under "Mycology" not only the Eumycetes but Bacteria and 

 Myxomycetes are described— a comprehensive arrangement which 

 -students of plant pathology will cordially welcome. A shorter 

 account of the nature and classification of Bacteria serves as a guide 

 to the discussion of these organisms as originators of plant diseases. 

 The Myxomycetes, or " slime moulds," have been determined as being 

 ■ more of an animal than a vegetable nature, hence the term " Myce- 

 tozoa " ; but they have always been of special interest to mycologists, 

 and the nearly related Plasmodiopliora causes the finger-and-toe 

 disease of turnips. A scab-disease of potatoes, Spongospora, is also 

 generally included among slime-moulds. 



The higher fungi — Eumvcetes — follow next ; their physiology, 

 •chemistry, histology, &c., receive due consideration, and the various 

 families are passed in review. A general text-book is not the place 

 for svstematie work, but in the appendixes, as has been stated, keys 

 to selected families or genera are given as exercises — a method which 

 leaves out large sections while giving undue importance to others ; 

 thus we are provided with a key to the species of PenicilUiini, but 

 no guide to the genera of Ascomycetes. We welcome the familiar 

 names in the key to Agaricacete and congratulate the author on his 

 adherence to accepted nomenclature. 



Much attention is given to fertilization in the different groups, 



